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Digital Video Cleaning without the Elbow Grease

Learning how to capture video is one thing. Cleaning it up is a whole 'nother …

Part 2 of 3: Video Cleaning featuring VirtualDub and the AviSynth frame server

Introduction

This guide is the second in a series on the Art of Video Capture, Clean-up, and Compression (Part I is here). This guide deals exclusively with the second step: Video Clean-up. While many of the lessons to be learned in this guide apply to all platforms, this guide is written from the perspective of PC-based hardware, running Microsoft Windows (and is largely MS OS version agnostic).

In Part 1, we covered the basic steps to properly capture video from an analog medium such as a television broadcast or your VHS VCR using a video capture card. We also mentioned that there are other ways to import your analog video to your computer via analog-to-digital DV bridges and DV cameras. Whichever way you get your video into your computer, this second part of the series will cover certain techniques such as Cutting, Cropping, De-interlacing, Inverse Telecine, Filtering, Noise Reduction, and Intermediary Recompression. Simply put, this guide will teach you how to clean up your video and set you up for final destination (compression), which will be covered in Part 3.

Capture Overview

In this guide we will be covering the following aspects of Video Clean-up:

Recommended
Computer Requirements

Downloading
and Installing the Required Software

AviSynth
and VirtualDub

Introduction to VirtualDub

Cutting and Cropping

Combing: What is it?

De-combing: The 2 Methods

De-interlacing

Inverse Telecine (IVTC)

When
to use each Technique

Basic Filtering and Noise Reduction

For most sources

For VHS video

Advanced Filtering and Noise Reduction

Using AviSynth

Decombing: When to use each Technique

Motion Compensation De-interlacing with AviSynth

Inverse Telecine (IVTC) with NTSC video

Performing Inverse Telecine with AviSynth

Decombing PAL/SECAM video

Deciding which method to use with PAL/SECAM

A Fancy Alternate Method

Hybrid Video Streams

The Advantage of AviSynth

AviSynth Noise Filters

The Filter Chain

Using the Crop() function

Further Experimentation

Intermediary Recompression

Recommended Computer Requirements

x86-based
PC with both MMX and SSE support

256+MB
RAM

40+GB
of Free HD space

Microsoft
Windows98/Me/2000/XP

These are the minimum recommended requirements to perform video clean-up on the Windows platform. It is entirely possible to do video clean-up with less than this configuration, but the elapsed time for clean-up will be significant longer. Some filters require that you have CPUs with MMX and/or SSE support. Obviously, a faster CPU, more RAM, and more HD space will make this job easier and faster.

Downloading the Required Software

All the pieces of software that we will be using, except for one, are freely downloadable. If you want to work through this as a tutorial, please download each specified software package, filter, and codec.

The PICVideo MJPEG codec was previously given away for free by Pegasus Imaging for non-commercial use. The latest versions of the PICVideo MJPEG codec can still be downloaded for free, but contain a watermark in the upper right corner of the video. The watermark-free codec can be licensed for a mere $18. Also note that AviSynth 2.0.x is NOT compatible with 2.5.x type filters. Nor can AviSynth 2.0.x and 2.5.x be installed at the same time either. For advanced users, it is possible to use 2.0.x filters with AviSynth 2.5.x, but it requires you to perform a somewhat complex LoadOldPlugins procedure. For now we just recommend that you download and install AviSynth 2.0.x and its respective 2.0.x filters.